Inflation Definition and 415 Threads

I am currently reading Max Tegmark's book "Our Mathematical Universe" in which he argues for an infinite number of parallel multiverses. It seems to me that the basis for his postulating the multiverses is that "eternal inflation" occurs and continues to occur in space regions even after a...

Dear PF, I'm trying to understand slow roll inflation from a layperson view, and I think my current understanding is mistaken. If a bubble of matter is trapped in a local minimum PE state, and begins to roll down a hill to a lower PE state, it strikes me that bubble will expand in size the...

Homework Statement An economist has predicted that for the next 5 years, annual inflation will be 8%, and then there will be 5 years at a 6% inflation rate. This is equivalent to what average price change per year for the entire 10-year period? Homework Equations The Attempt at a Solution...

Appreciated experts, I want to model the inflation of a thin and isotropic circular plastic membrane clamped by a ring. I need to determine the maximum deflection at the pole, stresses, strain, etc..., as a function of the applied pressure difference. The large deflection range complicates it...

Inflation theory, as far as I know, is completely ad-hoc (that is, created to fit already available data). What testable predictions does inflation theory make, and which of these have been confirmed to be accurate?

Hi Guys, After data release of Planck satellite , at least about early universe cosmology, nothing new except few( i.e Dipole asymmetry of the CMB temperature fluctuations ) in comparison to WMAP results was found. As a case existence of non Gaussianity at the level of squeezed limit has been...

According to the inflation theory there is a horizon where space is receeding so fast from an observer such that light will never reach the observer. First, I thought that matter could go equal to or faster than light. This being so, if A is receeding at 0.999...c and B is receeding at the same...

hi I want to solve inflation problem for exponential potential. v(\phi) = v_0 exp(-\alpha \phi) (it's known as barrow or pawer law inflation ) we have 2 main equations: H^2 = 8π G / 3 (1/2 (\dot{\phi})^2 + v(\phi)) \ddot{\phi} + 3H \dot{\phi} + v(\phi)'=0 I must solve this 2 equ...

Regarding scale. How big was the region of the universe we now understand to be the observable universe, immediately after early inflation? I'm tyring to understand the scale. I know our sphere of observation is very approximately 45 billion light years or something, I don't know for sure...

My question is regarding the early inflationary phase of the Big Bang. As I understand it, inflation is what gave rise to the expansion energy of the universe. Meaning, inflation gave the 'push' so to speak that set the everything moving apart. This makes sense because obviously the universe...

I was under the impression that the super inflation generated by the LQC was not enough to give us the 60 minimum e foldings for inflation to solve the horizon problem. However I have just noticed this paper on the arxiv today and I am wondering now if that conclusion is too hasty, any thoughts...

I write this in the hope that somebody reading this can explain to me, a laymen, in non-mathematical, plain English terms, why my thinking is wrong regarding the calculation of the age of the observable Universe and the formation of the elements in the Periodic Table given the (short) age of...

-In the first few fractions of a second after the big bang, was the universe finite and closed during early inflation, before it smoothed out and became flat and infinite? I am wondering because I would like to know if the theory implies that the universe initially inflated with a finite...

] arXiv:1310.2072 [pdf, ps, other] Intermediate inflation from rainbow gravity John D. Barrow, Joao Magueijo Subjects: Cosmology and Extragalactic Astrophysics (astro-ph.CO); General Relativity and Quantum Cosmology (gr-qc) It is possible to dualize theories based on deformed dispersion...

I've heard people say that a 4.0 GPA can look a bit suspicious to admissions committees for grad school. I'm wondering how true this actually is... I assume it depends greatly on whether the 4.0 is coming from a well known university. Let's say that the 4.0 is just coming from a large state...

I was looking at the wikipedia article about cosmic inflation (you know, the first 10-32 seconds). It says that an inflation hypothesis is a neat way to explain a number of otherwise puzzling observations, but it doesn't say much about what would make inflation occur and it doesn't mention...

I was thinking that "eternal inflation" model deals nicely with the problem of the beginning of the universe. If I understand this model correctly, Multiverse is a boiling bulk of some sort of very dense vacuum, creating inflationary "bubbles" (baby Universes), finite from the outside but...

Assuming that the early inflation of the universe is driven by the potential energy of some inflaton field(s), the "normal" matter is created only after this rapid inflation has stopped by conversion of the latent energy of the corresponding phase transition to particles. Does this mean that...

Hello here, I am currently working on the topic of inflation. It seems that at the stage of inflation, the universe can be described as a de Sitter space. In such a space, all spacetime diffeomorphisms are preserved. (That is something I don't really understand but I keep reading that so I...

according inflation, the universe should to be uniform in all directions at large scale, but observations from the Planck spacecraft found fluctuations in the cosmic microwave background that undermines the model. http://www.kavlifoundation.org/science-spotlights/kicc-planck-universe

Blackforest asked about an interesting paper recently posted by G.F.R. Ellis, that MTd2 spotted and added to our bibliography. I hope we can have some discussion of the Ellis paper. Unimodular gravity is a variant of the usual GR which is restricted to metrics which do not feel "vacuum...

There's a belief floating around that it takes "jumping through a lot of hoops" for a theoretical model to predict inflation AND give an adequate amount AND then stop . The conventional wisdom is it requires fine-tuning for inflation to turn on, go for at least 60 efolds, and then turn off, i.e...

It is often said that although the expansion of the universe may create the illusion of objects in very far regions of the universe to recede from each other at superluminal speed, that does not violate c because locally they never move faster than c. This I can understand. How would things...

Hello, In the early stages of Cosmic Inflation, immediately after the Big Bang, all matter was basically energy in a plasma form. It continued to expand for 380,000 years before cooling enough to form the first atoms. I have two questions: 1. Did this matter continue to exist in a...

I've been haqving a tough time tracking down which particular inflationary models form the basis of \LambdaCDM. the model I have discounted already is false vacuum A.Guth. some articles seem to suggest concepts from slow roll inflation. Others deal specifically with the inflaton field in...

Was it inflation that started off the universe to exist, or was it the Big Bang? The reason I ask is because from I've read is that the universe wasn't an explosion, but rather a rapid expansion. Was there a small explosion we call the big bang, then the cosmological inflation? Or was there...

Hi, I've been reading about inflation, and I'm not totally convinced about how it is proposed to result in a flat universe. If I understand it correctly, inflation expanded the universe so rapidly that the actual size of the universe now is 23 orders of magnitude larger than the observable...

Slides and audio for this talk by Brajesh Gupt were posted online today. LQC bounce creates conditions for inflation. It's important to extend the quantum bounce model to anistropic cases, such as Bianchi I. Anisotropy can affect what one expects from the ensuing inflationary episode. Here...

Was it gravity? Does the expansion of the universe have anything to do with the original inflation? One more. What actually is the "fabric" of space that is expanding? You always hear the balloon analogy, so what makes up the rubber of the balloon in real life? Thanks in advance for my...

I figure that we need a thread specifically for this topic, while we try to sort out just how minimal physics could be, in the wake of the Moriond conference on the Higgs and the data release from the Planck collaboration. Fedor Bezrukov has written many papers on Higgs inflation, and curiously...

I have had an idea kicking around in my head for some time now. It all started last summer when I was kayaking down a river and I had stopped in an eddy to relax for a moment. The rate of flow of the water was strong enough to make sizable vortices along the eddy fence around the boulder that...

Hi I know that gravitninos are produced in the Early Universe in reheating (after inflation), is this because the end of inflation/reheating period where the inflaton is oscillating about the minima of the potential is analogous to symmetry breaking?

Can anyone explain to me why after chaotic inflation with V=\frac{1}{2}m^2 \phi^2 that the inflaton behaves as; \phi=\frac{m_p}{m \sqrt{3\pi}t} \sin(mt). because this doesn't satify the slow roll conditions or the eqn of motion for the inflaton. I have read that it asymptotically approaches...

Hello all . I have two questions : 1 - Before inflation elementary particles such as matter and photons could not be created and destroyed or could be created and destroyed but could not be permanent ? I mean can we say matter existed before inflation but it was created and destroyed in...

Having read the 'The bigger bang' book two times over, I am struck by the fact that the author seems to ask and answer the question of quasar energy emission without stating he is doing so or explaining why it would be wrong to assume he is doing so. In the beginning of the book, Lindsey...

New to cosmology and somewhat confused. I get all the ideas indvidually, that inflation is the exponential growth in the beginning of the universe, than that gravity and matter cancel each other out to make the zero energy universe, and that a flat universe is the only one that is zero energy...

I saw this question (in a far removed forum), and I thought it was interesting. Do we have any theoretical reason (or observations) that would suggest that inflation change the fine structure constant.

I really think this paper http://arxiv.org/abs/1212.1087 which Chronos mentioned in another thread deserves its own thread. Has anyone had a chance to look at it? what do you think? This has been a lot of noise about this issue raised by people like Roger Penrose and Sean Caroll . They have...

The commonly accepted age of the universe is 13.7 billion years. I assume that assumes an inflationary epoch. Since inflation is in debate, what’s the age without it? And since expansion is accelerating, I assume expansion was slower 10 (or 20) billion years ago. Could it be infinitely old? (IE...

In brane cosmology how can there be no such thing as inflation. I was watching a lecture with Neil Turok and he said he made a bet with Hawking that says that the new Planck satellite will give us information that could prove against inflation. So, my question being, instead of inflation in the...

Does anybody know what is the status of supersymmetric inflation model after latest results of LHC concerning SUSY? Have some models been excluded? or do you know some review papers talk about that issue?

Before i begin, i will note that i truly don't have any idea of what I'm about to ask, but the questions elude me so ask i must. Firstly, Dark matter: finding it on earth. I've just finished watching a documentary on mapping our universe and within the program was shown a theory of trying to...

Hi Guys I've just made a sheet illustrating the horizon problem and how it is solved by inflation. I thought it might be handy for anyone interested in it, or having trouble with it. I'd also appreciate it if some of you could check it over and see if there's anything I have gotten wrong...

how much more power had big bang in inflation theory than in standard expansion theory? (if standard expansion big bang = 1 ) i assume it was over-c because of that power standard expansion would be 18000000 km/min and inflation... ? and after how much time did speed of light...

I understand what inflation is, but what are the reasons behind why scientists are near definitive that it indeed happened? Please go as in depth, complex, or over the top as you need/want.

How can inflation explain the particle horizon's problem?

I understand that (from what we can tell) the universe is expanding at an accelerating rate. I'm just curious if it's possible that the universe is expanding in some areas, and receding in others. despite this going against the cosmological principle, is it possible that beyond our bubble of...

This is from Krauss' A Universe from Nothing How could Guth know what density fluctuations arise after inflation? More context to better help a potential answerer:

This is from Krauss' A Universe from Nothing: It seems like he's saying that before inflation kicked in around 10^-36 or 10^-34 I forget which that the universe, I'm guessing from 10^-43 - 10^-36 was in some sort of false vacuum state, analogous to the way matter changes phase from gas to...

Why does inflation mean that the universe was much smaller at 380000 years after the big bang than we would predict from the Big Bang model alone? What would we expect the two sizes to be?